Grease compositions containing complex alkaline earth metal salts



Patented Apr. 30, 1957 GREASE COMPOSITIONS CONTAINING COMPLEX ALKALINEEARTH 'METAL .SALTS John J. Giammaria, Woodbury, N. J., assignor toSocony Mobil-Oil Company, Inc., a corporation or New York No Drawing.Application October 30, 1956, Serial No. 619,123

The present invention is concerned with grease compositions. Morespecifically, the invention is concerned with grease compositionscontaining novel gelling agents,

namely, complex alkaline earth metal salts of acetic acid and of partialesters of phosphoric acid.

This application is a continuation-in-part of application Serial No.354,406, filed May 11, 1953, now abandoned.

Recently developed for use as mineral lubricating oil detergents areoil-soluble, complex metal salts of organic acids such as formic, aceticand caproic acids and of partial esters of phosphoric acid. These saltsand lubrieating oil compositions containing the same are described byFerdinand P. Otto in applications Serial Nos. 246,501, filed September13, 1951 (now abandoned) and 541,849, filed October 22, 1955; andrelated zinc salts are described by Ferdinand P. Otto and Edmund W.Flynn in applications Serial Nos. 246,502, filed September 13, 1951 (nowabandoned), and 541,848, filed October 22, 1955.

I have now found that, while the complex metal salts described in theaforesaid applications are excellent additives for lubricating oils,they are not suitable for use as gelling agents for greases. This isparticularly so for greases subjected to high temperatures during use.However, I have now discovered a related class of novel complex metalsalts which are gelling agents of excellent character and particularlyeifective for high temperature greases. It is with such agents that thisinvention is concerned.

It is well known that greases lose some .or all of their effectivenesswhen subjected to high temperature operations. In lubricating machineparts, for example, it is essential that a grease retain its gelstructure during use; failure to do so results in high consumption ofthe grease and frequent servicing. In general, available greases sufferfrom a marked tendency to change in character when used over a widerange of temperature, particularly at high temperatures of the order of300-500 F. and higher. Some conventional greases are characterized byexcessive softening when exposed to such high temperature operation,thereby extruded too rapidly from the area being lubricated to provide.efiicient lubrication.

It is an object of this invention, therefore, to provide a greaseeffective .for .high temperature use, such as 200- 500 F. and higher. Afurther object is .to provide a grease which retains its originalcharacter over a wide 'range of operating conditions. Another object isto pro vide a novel group or class of gelling agents. Other objects ofthe invention will be apparent from the following description.

The gelling agents of this invention can be designated broadly ascomplex metal salts of partial esters of phosphoric acid and of aceticacid. The nature of these salts is unknown at this time and, therefore,no exact chemical formula can be ascribed to them. They can best bedescribed by the process for producing them.

The complex metal salts are prepared by first preparing a partial esterof phosphoric acid by the reaction of phosphorus pentoxide with analkyl-substituted hydroxyaromatic compound in which the alkyl portioncontains from eight to fourteen carbon atoms, preferably nine to twelvecarbon atoms. The ester is then reacted by either of three methods,viz.,

(1) Reacting a mixture of the ester and acetic acid with an alkalineearth metal hydroxide or oxide,

(2) Reacting the ester with a salt of an alkaline earth metal to formthe normal metal salt of the partial ester and then further reacting thenormal metal salt with an alkaline earth metal acetate, or

(3) Reacting the ester with a sufficient amount of alkaline earth metalacetate to provide the complex salt (i. e., without intermediaryformation of the normal salt).

In accordance with method (2), the metal salt reagent used to form thenormal salt need not be a carboxylate salt, but can be a hydroxide,carbonate or an alcoholate. However, the metal constituent of both saltreagents, i. e., the one utilized in forming the normal salt and thecomplex ,salt is preferably the same metal, and the latter salt reagentis preferably an acetate.

In each of the aforesaid methods, (1) through (3), a temperature of atleast about 400 F., and preferably 400500 F., is employed. The heatingperiod is generally from about 0.1 to about 2 hours. However, apreferred procedure involves preparation of the desired complex metalsalts in .oil. In the preferred procedure, the partial esters and aceticacid are blended with suiticient mineral oil to give 15 to 25 percent ofthe desired complex .salt in the finished grease. An alkaline earthhydroxide, in .an amount sufficient to at least neutralize all the acidsemployed, is then added and the resulting mixture is heated to 400-500F. to form the grease. The grease is cooled statically or with stirring,and is milled to a smooth consistency.

As indicated above, in View of the complex nature of the reactionsinvolved in the formation of the complex metal salts, theirexactstructure is not yet known. The complexity .of these salts is indicatedby the complexity of the esters from which they are prepared.

When an alkylated hydroxyaromatic compound, such as an alkyl phenol isreacted with phosphorous pentoxide in a 3:1 mol ratio, indications arethat the product consists essentially of a mixture of:

p 1) Mono-alkaryl phosphoric acids (2) Di-alkaryl phosphoric acid and(3) pyrophosphoric acids such as di-alkaryl pryo phoric acid (EH OHR--.01|TO1TOR in the mixture is increased.

Alkyl hydroxyaromatic compounds suitable for preparing the partialesters contemplated herein can be represented by the general formula:

wherein A is an aromatic nucleus or group such as phenyl. naphthyl,etc.; R is an alkyl. group containing from eight to fourteen carbonatoms, and is preferably i of branched-chain configuration; and n is asmall whole number from one to two, preferably one. Preferred of suchcompounds are alkyl phenols having from nine to twelve carbon atoms inthe alkyl group. Nonylphenol is especially preferred.

As is well known in the art, such alkylhydroxyaromatic compounds can beprepared by alkylation of a hydroxyaromatic compound, such as phenol.Alkylation of the aryl hydroxide can be accomplished by methods such asa Friedel-Crafts synthesis using a halogenated compound. Alkylation canalso be effected by reaction of the aryl hydroxide with unsaturatedhydrocarbons, or alcohols, in the presence of a suitable catalyst, suchas H2504, ZnClz, BFs, HF, etc.

Typical aryl hydroxides or phenols which may be used as the startingmaterial for the alkylation reaction are: phenol, resorcinol,hydroquinone, catechol, crcsol, xylenol, hydroxydiphenol, benzylphenol,phenyl-ethyl-phe nol, phenol resins, methyl-hydroxydiphenyl, guaiacol,alpha and beta naphthol. alpha and beta methyl naphthol, tolyl naphthol,xylyl naphthol, benzyl naphthol, anthranol, phenyl methyl naphthol,phenanthrol, chlorphenol and the like. Preference is given to phenol.

In preparing the alkaryl phosphoric acid ester, the alkylhydroxyaromatic compound and P205 are heated together at a temperatureof from about 50 C. (122 F.) to about 150 C. (302 F.) for a period oftime to insure substantially complete reaction, usually from about fiveto fifteen hours. An inert solvent, such as toluene, xylene or the like,can be used to facilitate the reaction. A mineral oil can also be usedas the solvent, in which case the product is an oil concentrate whichcan be used directly in the preparation of the complex metal salt andultimately in the preparation of the desired gelling agent. In this waythe ultimate gelling agent is obtained in the form of an oil concentrateand can be conveniently utilized as such for preparation of greases.When a solvent other than mineral oil is used, the P205 reaction mixtureis filtered and topped at elevated temperature and reduced pressure toremove the solvent.

The proportions of alkyl hydroxyaromatic compound and P205 used in thereaction can be varied between from about one to about three mols of thealkyl hydroxyaromatic compound to one mol of P205. In general, the useof a 2:1 ratio yields a complex salt with acetic acid which has greatergelling power.

As indicated previously, in preparing the complex metal salt of thephosphoric acid ester, the normal salt can be prepared first by reactionof the ester with a suitable metal salt, such as a hydroxide, carbonate,alcoholate, etc. The complex salt can then be formed by further reactionof the normal salt with an alkaline earth metal acetate, preferably ofthe same metal constituent as the metal salt reagent used in theformation of the normal ester salt. Also, the complex salt can beprepared directly by reacting the ester with a sufficient amount of analkaline earth metal acetate salt to provide twice the amount of metalwhich would be equivalent to the acid-hydrogen content of the phosphoricacid partial ester. However, the most advantageous method involvesreacting a mixture of acetic acid and partial ester product with analkaline earth metal hydroxide, wherein the hydroxide is used in anamount at least suflicient to neutralize the acetic acid and partialester product.

4 The proportions of esterand acetic acid to be used in preparing thegelling agents can be varied over a fairly wide range. In general, it ispreferred to use an amount '4 of acetic acid equivalent to the ester onthe basis of neutralization number. The amount of acetic acid can bereduced to about fifty percent of this amount, but increasing it muchabove the equivalent amount results in the formation of greases whichare excessively fluid and which are unsatisfactory for high temperatureuse.

The reactions required to produce the complex salts by any one of themethods recited above, are within the skill of those familiar with theart. The reactions are accomplished at temperatures of from about 400 F.to about 500 F., in a relatively short time, generally from about 0.1hour to 2 hours. A suitable solvent medium, such as benzene, toluene,xylene and the like, or a min eral oil can be used as the solvent. Inthe latter case, an oil concentrate of the complex salt is obtained.

The preferred method, however, involves preparation of the desiredcomplex metal salts in oil. The partial esters and acetic acid areblended with sufficient mineral oil to give 15 to 25 percent of thedesired complex salt in the finished grease. An alkaline earth metalsalt reagent in an amount sufficient to at least neutralize all theacids employed, is then added and the resulting mixture is heated to400-500 F. to form the grease. The grease is cooled statically or withstirring, and is milled to a smooth consistency.

Alkaline earth metals are employed in forming the gelling agents of thisinvention, particularly calcium and barium. Calcium is preferred in viewof its lower cost. The hydroxides are preferred for neutralizing themixture of alkaryl phosphoric and acetic acids to form the gellingagents.

Several illustrative but non-limiting examples of some specific gellingagents and greases containing the same are set forth below. In theexamples, all parts are by weight unless otherwise described.

EXAMPLE I Calcium grease 0f nonylphclzol-PzOs product (3 :1 ratio) andacetic acid A nonylphenol-PzOs product was prepared by adding 0.33 molarproportion of P205 in small portions to 1.0 molar proportion ofnonylphenol at 200 F., while mechanically stirring the mixture whichformed. After the addition of P205 was completed, the temperature wasraised to 300 F. and was so maintained for about three hours. Theviscous product was then filtered through a thin layer of filtering clay(Hy-flo clay) on a heated Buchner funnel. The product-the filtratehad aneutralization number of 195, and contained 7.6 percent of phosphorus.

Five parts of this product, one part of glacial acetic acid, 1.4 partsof Ca(OH)2 and 20 parts of a solvent refined naphthenic oil having aviscosity of 513.5 SUS (Say' bolt Universal seconds) at F., were mixedand were heated with constant stirring. The resultant mixture began tothicken at 410 F. and formed a heavy gel at 420 F. The mass was stirredwhile it was cooled to room temperature, after which the heavy grainygel which resulted was milled to a smooth consistency.

EXAMPLE lI Calcium grease of nonylphenol-PzOs product (3:1 ratio) andacetic acid This grease was prepared by the procedure described inExample 1 above, except that the proportions of reactants were increasedtwenty-fold. The heavy grease so obtained was blended with additionalmineral oil parts) to reduce the soap content to twenty percent(weight). This blend was put through a colloid mill. The final greasehad a buttery consistency.

EXAMPLE III Calcium grease of nonylphenol-PzOs product (3:1 ratio) andacetic acid One hundred parts of a nonylphenol-PzOs product similar tothat which is described in Example I, above, ten parts of glacial aceticacid (fifty percent of the amount used in Examples I and II), twenty-twoparts of Ca(OH)2 and four hundred parts of a solvent refined naphthenicoil having a viscosity of 513.5 SUS at 100 F., were mixed in a greasekettle and heated. A temperature of about 500 F. was required to form agel. Heating was continued for about five minutes after the gel hadformed. The product was then cooled to room temperature (about 75 F.)while it was stirred. The resulting grease was quite heavy inconsistency and dark in color.

EXAMPLE IV Calcium grease of nonylphenol-PzOs product (3:1 ratio) andacetic acid This grease was prepared in the same manner as the grease ofExample III, except that twenty-five parts of glacial acetic acid andthirty-one parts of Ca(OI-I)z were used. In this case, gelation occurredat about 415 F.

EXAMPLE V Calcium grease of nortylphenol-PzOs product (2:1 ratio) andacetic acid A nonylphenol-PzOs product was prepared in the same manneras the corresponding product described. above in Example I; however,here, 0.5 molar proportion of P205 was used per molar proportion ofnonylphenol. The product so obtained had a neutralization number of 207and was considerably more viscous than the product pre pared with a 3:1ratio.

One hundred parts of the 2:1 product, 22.2 parts of glacial acetic acid,30.0 parts of Ca(OH) 2, and 400.0 parts of a solvent refined naphthenicoil having a viscosity of 513.5 SUS at 100 F., were charged to a greasekettle and were heated. Gelation occurred at about 425 F.

EXAMPLE VI Barium grease of nonylphenol-PzOs product (3:1 ratio) andacetic acid cooled to about 75 F. and was put through a. colloid mill.

The resulting grease was smooth and: of heavy consistency.

EXAMPLE Vll Calcium grease of dodecylphenoi-Pzos product (3:1 ratio) andace-tic acid A dodecylphenol-PzOs product was prepared in the mannerdescribed in Example I, above. The neutralization number of the productso obtained was 170'.

One hundred parts. of. this dodecylpheno -P2Q5 product,

1717 parts of glacial acetic acid, 25.0 parts of a(OH )z"- and 400.0parts of solvent refined naphthenic. oil having a viscosity of 5,1 3.5SUS atv 100 F, were charged to a grease kettle and were heated to. 445F. during a period of 1-2 hours, whereupon gelation occurred. Afterheating the mixture for about ten minutes at 445 F., the resulting heavygrease was cooled toroom temperature (about 75 F.) while it was stirred.The grease was, blended with 100 parts. of the. oil described above. anda.

rather soft,v adhesive grease was formed- EXAMPLE VIII Calcium grease oftetradecylphenol-PzOs product (3:1 ratio) and acetic acid Atetradecylphenol-PzOs product was prepared by the procedure described inExample I, above. The product so prepared had a neutralization number of150.

One hundred parts of this tetradecylphenol-PzO product, 16.1 parts ofglacial acetic acid, 22.0 parts of Ca(OH)z and 375.0 parts of solventrefined naphthenic oil having a viscosity of 513.5 SUS at 100 F. werecharged to a grease kettle and were heated to about 470 F. during aperiod of 1-2 hours, whereupon gelation occurred. The mixttu'e washeated at about 470 F. for about five minutes, then the grease wascooled to room temperature (about F.) while it was stirred.

EXAMPLE IX Calcium grease from n uylphenol-P2O5 product (2:1 ratio) andexcess calciun'z acetate A mixture of parts of nonylphenol-PzOs product(described in. Example V), 6.5 parts of calcium acetate and 40.0 partsof a solvent refined naphthenic oil having a viscosity of 5l3.5- SUS at100 F, was heated with stirring. Foaming occurred between 200 and 400 F.Foamsubsided at 400 F. and the mixture was very fluid. It became moreviscous at MO-450 F. and set to a coarse, grainy gel. It was cooled toroom temperature and milled to a fairly smooth grease.

EXAMPLE X Calcium grease from the calct'zmt salt 0 nonylphenol- P205product (2:1 ratio) and calcium acetate A mixture of 10.0 parts ofnonylphenol-PzOs product (described in Example V), 1.37 parts ofCa(OH.)z and 40.0 parts of oil (as in Example 1.), was heated withstirring to 350 F. to form the calcium salt of the partial ester ofphosphoric acid. This was cooled to F. and 325 parts of calcium acetatewere added. The mixture was reheated with stirring. It remained fluid upto 450 F. It began to thicken at this point and form a soft, grainy gelat 450-460 P. On cooling to room temperature, it was milled to a fairlysmooth, somewhat softer greasethan Example IX.

In general, the. greases of this invention are characterized by highdropping points, which fact indicates their use for high temperatureapplications. The dropping points and penetration values, of the greasesdescribed above are listed in Table I below.

TABLE I A. S. '1. MA A. S. l.. M?

Grease Penetration, Dropping IIlIIL/lO Point, F.

Example I 450 Example II. 290 440 Example III. 285 460 Example IV. 320410 Example. V. 460 Example VI 225 340 Example VII 1 345 485 ExampleVIII '360 135 1 A. S. '1. M. Designation 1) 217-48. 'A. S. T. M.Designation D 560-42.

The data presented in Table I reveals that the greases illustrative ofthe invention are suitable for high temperature applications. Incontrast, the grease of Example VII-I, derived from tetradecylphenol,has an unsatisfactory dropping point value, as low as 135 F, and has arather high penetration value (360). These unsatisfactorycharacteristics are ascribed, in part at least, to the excessive lengthof the alkyl chain, tetrad'ecyl of the alkylphenol. As indicated above,the maximum number of carbon atoms in said alkyl chain is preferablyabout twelve.

illustrative Examples I through VIII are presented'in TABLE II paratusemployed is described in the Institute Spokesman, 6, No. 12, page 4,March 1943. The procedure followed in this test is given below:

1. Work 99 grams of grease and 1 cc. of distilled water Greases ofalkaline earth metal c mplexes of alkylphenol- P205 products and aceticacid I Reactants (Parts by Wt.) Properties of Grease Example No.Gelation Alkylphenol-P O Acetic Metal Temp, F. A. S. T. M. A. S. T. M.

Product Acid Hydroxide Oil Penetration, Dropping mun/l0 Point, F.

23 30 (Ga)... 400 22 (Ca)... 400 I5 26 (Ga)... 5

20 28 (Ga)... 500 22.2 30 (0a).... 400 31 (0a).... 400 100 (C (Ca)...400 100 (Cu n. 40 (C11)... 400 100 (Cu) 20 110 833).. 400 100 (C-Diumyl)... 17. 7 25 a). 400 100 (Cu) 17.7 25 (Ga)..- 500 16.1 22(0a)--.- 875 ll. 0 15 (Ca). 400 13.3 20 (0a).. 400

1 Ratio of Alkylphenol to P O; ls (3:1) in all cases except No. V whichis (2:1). Alkyi group in Alkylphenol ts branched in all cases except No. XIV

A number of observations can be made from the data I set forth in TableII. Examples I-V and XVII involve a nonylphenol-PzOs product, and allgreases derived therefrom are of excellent character. Thus, a nonylalkyl group and the nonylphenol-PzOs product are preferred. In contrast,the octylphenol-PzOa product (Example XVI) failed to form a grease.Diamyl phenol (Example XIII), tetradecylphenol (Example VIII),pentadecyl phenol (Example XIV), and wax phenol (Example XV), eitherfailed to yield a grease or the grease was unsatisfactory in that it wastoo soft in consistency.

Examples I-V and XI, XII and XVII illustrate the effect of varying theamount of acetic acid on the calcium base grease. The use of 15 to 25parts of acetic acid to 100 parts of the nonylphenol-Pzos product, ispreferred since greases of good consistency and high dropping points areformed at the lower temperatures, 415- 435 F. When the amount of aceticacid was reduced to 10 parts (Example III), a temperature of 500 F. wasrequired to form the grease, while 30 to 40 parts of acetic acid(Examples XI and XII) failed to yield a grease.

A comparison of Example V with Example IV, indi- -on a glass plate witha spatula until the droplets of water disappear into grease.

2. Transfer the wet grease to a 3 ounce asphalt tin and cool the sampleto 77 F.

3. Scrape off the excess grease from the top of the tin with the bladeof the spatula and determine the penetration of the grease, using themicropenetration cone and shaft assembly (weight 58.3 grams).

4. Charge the rolling stability test cylinder with grams of the wetgrease and distribute the grease uniformly on the inside walls of thecylinder. Place the Weighted roll in the cylinder and screw the cylindercap on tightly.

5. The grease is worked in the cylinder at room temperature for a periodof 2 hours.

6. At the end of the rolling time period, disassemble the apparatus.Remove the rolled grease from the cylinder and roller with a spatula andtransfer the grease to a 3 ounce tin for penetration measurement. Cooltherol-led grease to 77 F. within 15 minutes and determine themicropenetration.

The .description of the equipment used in determining oil separation,subsequent to the rolling stability test, is describedin the InstituteSpokesman, volume XI, No. 7, pages 4-5, October 1947, r

. Results of this severe test are shown in Table III below:

cates that the use of a 2:1 ratio (Example V) of alkylphenol to P205instead of a 3:1 ratio, is responsible for a grease of heavierconsistency.

Calcium is the preferred metal, since barium (Example VI) lields agrease of much lower dropping point, although still in the rangesuitable for a high temperature grease.

To further illustrate the excellent character of the instant gellingagents and greases containing the same, grease II shown above in TableII was subjected to a severe test. The grease was evaluated for shearstability in the presence of water The rolling stabilitytest ap- GreaseII, therefore, was satisfactory in all respects in this test.

In summary, it can be stated that the preferred gelling agent of thisinvention is the complex calcium salt of a mixture of nonylphenolP2O5acid product (2:1 ra-: tio or 3:1 ratio) and acetic'acid in whichapproximately equivalent amounts of the two acids are used based onneutralization number, and in which the acids are reacted with calciumhydroxide in an amount at least sulficient to neutralize the acids, saidgelling agent being formed at a temperature of 400-450 F. in thepresence of mineral oil. The amountof gelling agent. to be usedinforming a grease can vary from about ten percent to about fiftypercent. In general, fifteen to twenty-five percent is a suitableconcentration.

OIL VEHICLES The oil vehicles or oleaginous vehicles of the greases ofthis invention can vary considerably in character. In general, mineraloils used are those characterized by a viscosity (S. U. S.) of greaterthan about 40 seconds at 100 5., preferably from about 60 to about 6000seconds at 100 F. In place of all or part of the mineral oil component,other oils of lubricating viscosity can also be used. Such oils includesynthetic vehicles compris ing polymerized olefins, esters of aliphaticdibasic acids, esters of polyalcohols and monocarboxylic acids,silicones, silicate esters, esters of phosphorus-containing acids,fluorocarbons, etc. Typical of such synthetic oils are: polypropylene,polypropylene glycol, di(-2-ethyl hexyl) sebacate, phthalate,polyethylene glycol di(-2-ethy-1 hexoate), polymethylsiloxane. Thesynthetic vehicles are most: suitable for providing greases for use inaircraft, since many of such greases require lubricating value over atemperature range, from about -l F. to about 500 F.

MODIFYING AGENTS it is to be understood that the greases of thisinvention can also contain other characterizing materials and fillers.For example, the greases can contain anti-oxidants such as amines (e. g,phenyl alpha-naphthylamine), phenols (e. -g., 2-6-di-tertiarybutyl-4-methyl phenol), and the like; lubricity improving agents such asfiree fiat, free fatty acids, esters of alkyl and/0r aryl acids,sulfurized iats, lead soaps, etc. Typical fillers include carbon black,silica flour and colloidal clay. Other additives which can be. presentare: extreme pressure agents, such as a chloro naphtha xanthate; andtackiness agents such as poly-isobutylenes.

UTILITY The greases of this invention are suitable for a wide range ofindustrial applications. Some, for example, are suitable for use asmultipurpose automotive greases, serving as chassis, wheel-bearing,water-pump grease lubricants. Others are multi-purpose industrialgreases serving as plain-bearing land anti-friction greases for normallyloaded and heavily loaded equipment. In general, then, greasescontemplated herein range from semi-fluid types suitable as textilemachinery lubricants, to solid block type greases used in lubrication ofmachinery in steel mills, paper mills, cement mills, etc.

I claim:

1. A grease comprising an oleaginous lubricant and a gelling agent in anamount suflicient to thicken said vehicle to form a grease, said gellingagent being prepared by the steps of: (1) reacting one molar proportionof phosphorus pentoxi'de with from about one to about three molarproportions of an alkyl hydroxyarom-atic compound of the general formulaRA(OH)n wherein R is an alkyl group containing from eight to fourteencarbon atoms, 11 is a small Whole number from one to two, and A is anaromatic nucleus, to form an acidic, partial ester of phosphoric acid,and (2) forming a mixture of the acidic, partial ester obtained by step(1) and a quantity of acetic acid from about fifty percent to about onehundred percent equivalent to said lacidic, partial ester on the basisof neutralization number, and (3) reacting the mixture formed in step(2) with an alkaline earth metal compound selected from the groupconsisting of an oxide and a hydroxide, at a temperature between about400 F. and about 500 F., the amount of said metal compound being atleast sufiicient to neutralize the acetic acid and the acidic, partialester.

2. A grease comprising an oleaginous lubricant and a di,(-2v-ethylhexyl). adipate, dibutyl gelling agent, in an amount suflicient tothicken said vehicle to form a grease, said gelling agent being preparedby the steps of: (1) reacting one molar proportion of phosphoruspentoxide with inom about one to about three molar proportions of analkyl hydroxyarcmatic compound of the general formula R-A(OH )n whereinR is an alkyl group containing from eight to fourteen carbon atoms, n isa small whole number from one to two, and A is an aromatic nucleus, toform an acidic, partial ester of phosphoric acid, and (2) reacting theacidic, partial ester of step (1) with a quantity of an alkaline earthmetal salt to form the corresponding normal metal salt of said acidic,partial ester, and (3) reacting the said normal metal salt with analkaline earth metal acetate at a tempenature between about 400 F. andabout 500 F.

' A is an aromatic nucleus, to form an acidic, partial ester ofphosphoric acid, and (2) reacting the acidic, partial ester of step (1)with an alkaline earth metal acetate at a temperature between about 400F. and about 500 F., the amount of said acetate being sufficient toprovide twice the amount of alkaline earth metal equivalent to theacidhydrogen content of said acidic, partial ester.

4. A grease as defined by claim 1 wherein the all-:yl hydroxya-romaticcompound is nonylphenol.

5. A grease as defined by claim 1 wherein the alkaline earth, metal iscalcium.

6. A grease as defined by claim 1 wherein the gelling agent comprisesfrom about ten percent by weight to about fifty percent by weight ofsaid grease.

7. A gelling agent prepared by the steps of: (1) reacting one molarproportion of phosphorus pentoxide with from about one to about threemolar proportions of an alkyl hydroxyaromatic compound of the generalformula R-A-(Ol-l)n wherein R is an alkyl group containing from eight tofourteen carbon atoms, 71 is a small whole number from one to two, and Ais an aromatic nucleus, to form an acidic partial ester of phosphoricacid, and (2) forming a mixture of the acidic, partial ester obtained bystep (1) and. a quantity of acetic acid from about fifty percent toabout one hundred percent equivalent to said acidic, partial ester onthe basis of neutralization number, and (3) reacting the mixture formedin step (2) with an alkaline earth metal compound selected from thegroup consisting of an oxide and "a hydroxide, at a temperature betweenabout 400 F. and about 500 F, the amount of said metal compound being atleast sufficient to neutralize the acetic acid and the acidic, partialester.

8'. A gelling agent prepared by the steps of: (1) reacting one molarproportion of phosphorus pentoxide with from about one to about threemolar proportions of an alkyl hydroxyaromatic compound of the generalformula R-A-(Ol-l)n wherein R is an alkyl group containing from eight tofourteen carbon atoms, n is a small whole number from one to two, and Ais an aromatic nucleus, to form an acidic, partial ester of phosphoricacid, and (2) reacting the acidic, partial ester of step (1) with aquantity of an alkaline earth metal salt to form the correspondingnormal metal salt of said acidic, partial ester, and (3) reacting thesaid normal metal salt with an alkaline earth metal acetate at atemperature between about 400 F. and about 500 F.

9. A gelling agent prepared by the steps of: (l) reacting one molarproportion of phosphorus pentoxide with from about one to about threemolar proportions of an alkyl hydroxyaromatic compound of the generalformula RA--(OH)n wherein R is an alkyl group containing to form anacidic, partial ester of phosphoric acid, and (2) reacting the acidic,partial ester of step (1) with an "alkaline earth metal acetate at atemperature between about 400 F. and about 500 F., the amount of saidacetate being suflicient to provide twice the amount of alkaline earthmetal equivalent to the acid-hydrogen content of said acidic, partialester.

10. A gelling agent as defined by claim 7 wherein the alkylhydroxyaromatic compound is nonylphenol.

11. A gelling agent as defined by claim 7 wherein the alkaline earthmetal is calcium.

12. A grease comprising a mineral oil having a viscosity from about 100to about 1000 S. U. S. at 100 F. and a gelling agent in an amount ofabout fifteen to about twenty-five percent by weight of said grease,said grease being prepared by the steps of (1) reacting P205 with analkyl phenol wherein R is an alkyl group containing from nine to twelvecarbon atoms, to form an acidic, partial ester of phosphoric acid, and(2) adding to the partial ester obtained by step (1) a quantity ofacetic acid from about fifty percent to about one hundred percentequivalent to said acidic, partial ester on the basis of neutralizationnumber, and a quantity of said mineral oil such that the finished greasecontains from about fifteen to about twenty-five percent by weight ofsaid gelling agent, and (3) reacting the mixture formed in step (2) withan alkaline earth metal hydroxide, in an amount sufiicient to at leastneutralize all of the acids of the mixture formed in step (2), and (4)heating the resulting mixture of step (3) to a temperature from about400 F. to about 500 F., to form said grease, and (5) cooling said greaseand milling said grease to a smooth consistency.

13. A grease comprising a mineral lubricating oil and a gelling agent inan amount sutficient to thicken said oil to form a grease, said gellingagent being prepared by the steps of (l) reacting phosphorus pentoxidewith nonylphenol, the molar ratio of said phenol to said pentoxide beingabout. 3: 1, to form an acidic, partial ester of phosphoric acid, and(2) forming a mixture of the acidic, partial ester obtained by step (1)and a quantity of acetic acid about fiflty percent equivalent to saidacidic, partial ester on the basis of neutralization number and aminera1 lubricating oil, and (3) reacting the mixture formed in step (2)with calcium hydroxide at a temperature of about 500 F., the amount ofsaid calcium hydroxide being about equivalent to neutralize the aceticacid and the acid, partial ester.

14. A grease comprising a mineral lubricating oil and a gelling agent inan amount sufficient to thicken said oil to form a grease, said gellingagent being prepared by the steps of (1) reacting phosphorus pentoxidewith nonylphenol, the molar ratio of said phenol to said pentoxide beingabout 2: 1, to form an acidic, partial ester of phosphoric acid, and (2)forming a mixture of the acidic, partial ester obtained by step (1) anda quantity of acetic acid about equivalent to said acidic, partial esteron the basis of neutralization number, and a mineral lubricating oil,and (3) reacting the mixture formed in step (2) with calcium hydroxideat a temperature of about 500 R, the amount of said calcium hydroxidebeing about equivalent to neutralize the acetic acid and the acid,partial ester.

15. A grease comprising a mineral lubricating oil and a gelling agent inan amount sufiicient to thicken said oil to form a grease, said gellingagent being prepared 'by the steps of (1) reacting phosphorus pentoxidewith I'bricating oil, and (3) reacting the mixture formed in step (2)with barium hydroxide at a temperature of about 500 F., the amount ofsaid barium hydroxide being about equivalent to neutralize the aceticacid and the acid, partial ester.

16. A gelling agent prepared by the steps of 1) reacting phosphoruspentoxide with nonylphenol, the molar ratio of said phenol to saidpentoxide being about 3:1,

to form an acidic, partial ester of phosphoric acid, and

(2) forming a mixture of the acidic, partial ester obtained by step 1)and a quantity of acetic acid about fifty percent equivalent to saidacidic, partial ester on the basis of neutralization number, and amineral lubricating oil, and (3) reacting the mixture formed in step (2)with calcium hydroxide at a temperature of about 500 F., the amount ofsaid calcium hydroxide being about equivalent to neutralize the aceticacid and the acid, partial ester.

17. A gelling agent prepared by the steps of (1) reacting phosphoruspentoxide with nonylphenol, the molar ratio of said phenol to saidpentoxide being about 2:1, to form an acidic, partial ester ofphosphoric acid, and (2) forming a mixture of the acidic, partial esterob- .tained by step (1) and a quantity of acetic acid about equivalentto said acidic, partial ester on the basis of neutralization number, and(3) reacting the mixture .formed in step (2) with calcium hydroxide at atemperature of about 500 F., the amount of said calcium hydroxide beingabout equivalent to neutralize the acetic acid and the acid, partialester,

References Cited in the file of this patent UNITED STATES PATENTS2,200,299 Robinson May 14, 1940 M 2,228,659 Farrington et a1. Jan. 14,1941 2,322,307 Neely et al -1 June 22, 1943 1 2,329,707 Earring-ton etal Sept. 21, 1943 2,409,774 Mack et a1. Oct. 22, 1946

1. A GREASE COMPRISING AN OLEGINOUS LUBRICANT AND A GELLING AGENT IN ANAMOUNT SUFFICIENT TO THICKEN SAID VEHICLE TO FORM A GREASE, SAID GELLINGAGENT BEING PREPARED BY THE STEPS OF: (1) REACTING ONE MOLAR PROPORTIONOF PHOSPHORUS PENTOXIDE WITH FROM ABOUT ONE TO ABOUT THREE MOLARPROPORTIONS OF AN ALKYL HYDROXYAROMATIC COMPOUND OF THE GENERAL FORMULAR-A-(OH)N WHEREIN R IS AN ALKYL GROUP CONTAINING FROM EIGHT TO FOURTEENCARBON ATOMS, N IS A SMALL WHOLE NUMBER FROM ONE TO TWO, AND A IS ANAROMATIC NUCLEUS, TO FORM AN ACIDIC, PARTIAL ESTER OF PHOSPHORIC ACID,AND (2) FORMING A MIXTURE OF THE ADIDIC, PARTIAL ESTER OBTAINED BY STEP(1) AND A QUANTITY OF ACETIC ACID FROM ABOUT FIFTY PERCENT TO ABOUT ONEHUMDRED PERCENT EQUIVALENT TO SAID ACIDIC, PARTIAL ESTER ON THE BASIS OFNEUTRALIZING NUMBER, AD (3) REACTING THE MIXTURE FORMED IN STEP (2) WITHAN ALKALINE EARTH METAL COMPOUND SELECTED FROM THE GROUP CONSISTING OFAN OXIDE AND A HYDROXIDE, AT A TEMPERATURE BETWEEN ABOUT 400*F. ANDABOUT 500*F., THE AMOUNT OF SAID METAL COMPOUND BEING AT LEASTSUFFICIENT TO NEUTRALIZE THE ACETIC ACID AND THE ACIDIC, PARTIAL ESTER.